Collapsible rod



5 Sheets-Shoot 1 w fl INVENTOR. William @ubilier ATTORNEY.

Sept. 20, 1938. w. DUBILIER 2,130,993

COLLAPSIBLE ROD Filed Qct. 16, 19:56 5 Sheets-Sheet? INVENTOR. William Jubilier fie,

ATTORNEY.

W. DUBILIER COLLAPS IBLE ROD Sept. 20, 193&

Filed Oct. 16, 1936 5 Sheets-Sheet 3 &

INVENIOR.

William @ubilier BY ATTORNEY.

v w. DUBILIER 2,130,993

COLLAPSIBLE ROD Filed Oct. 16, 1936 5 Shasta-Sheet 4 mvmon Willa-am JDubp'lier ATTORNEY.

Sept. 20, 1938. w DUB|| |ER 2,130,993

COLLAPSIBLE ROD Filed Oct. 16, 1956 s Sheets-Sheet INVENTOR. 1719117 William @ubilier' I %M fie,

ATTORNEY.

Patented Sept. 26,1938- COSEIBLE ROD am Dubilier, New Rochelle, N. if.

Application October 16, 1936, Serial No. 105,94d

lln. Great Bri July 2, 1936 it claims. (or. 189-14) The present invention relates to collapsible structures, more particularly to extensible and collapsible rod structures or the like and. has for its object to provide an improved form of structure of this type which normally occupies relatively small space and may be conveniently accommodated in a box or casing so that it is readily portable and yet can be extended to form: a rigid, mechanically strong rod or pole suitable for varions uses, such as wireless antenna, a ladder.

fishing rod and the like.

The invention consists in the features of construction, combination oielements and arrangement of parts which will be exemplified in the construction hereinafter described, and which are illustrative of the improvements and novel features of the invention but which, as will become evident, are susceptible of numerous variations and modifications differing from the specific constructions and details shown and coming within the broad scope and spirit of the invention as defined in the appended claims.

The term rod is used herein to include any structure of equivalent type such as poles, masts, posts, or pillars, etc., which normally require comparatively large space for storing and are inconvenient to handle and transport,

In the accompanying drawings, Figure 1 is a front view partly in cross-section of a collapsible 4 3o mast or rod structure shown during its erection.

Figure 2 is a horizontal cross-sectional view taken on line 2--2 of Figure 1.

Figure 3 is a cross-section taken on line 3-3 of Figure 2. 5 Figure 4 is a partial sectional view taken on line 4-4 of Figure 2.

Figure 5 is a cross-section taken on line 5-5 of Figure 1. q

Figure 6 is a partial section taken'on line i--i 40 of Figure 2.

Figure '7 is a partial view taken on line 11 of Figure 3. I

Figure 8 is a partial view taken on line 8-4 of Figure 3. j 45 Figure 9 is a section through the rod taken on line 9-9 of Figure 1.

Figures 10 and 10a are plan and cross-sectional views showing the upper end of the rod.

Figure 11 is a perspective view showing the 50 construction of the rod.

Figure 12 is a fractional view showing one of the tape members of which the rod is composed. Figures 13 and 14 are partial plan and sectional views'showing features of construction for sup- 55 porting the rod or mast by guy wires.

Figures 15 and 16 illustrate diagrammatically a portable, collapsible antenna for wireless apparatus constructed in accordance with the in vention.

Figure 1'7 is a diagram illustrating the inven- 55 tion as embodied 'in a collapsible radio antenna built in a motor car for transportable wireless stations.

Figures 18 and 19 illustrate diagrammatically the utilization of a structure according to the inm vention as a collapsible ladder.

- Figures 20 and 21 illustrate an alternative-construction of tape members forming the elements of the collapsible rod.

Figure 22 illustrates a further multiplication for lit connecting and locking the tapes forming the rod according to the invention.

Similar reference characters identify similar parts throughout the different viewsof the drawings. 20

The improved extensible rod according to this inventioncomprlses three or more tapes or strips of a flexible .springy material, such as spring steel, each capable of being wound into a roll, arranged to form a hollow rod with each tape 5 constituting one side or wall of the rod and means whereby the engaging sides of adjacent tapes can be held together when the rod is extended but can be released to permit collapse of the rod. Preferably the tapes are of the type having a g curved or concavo-convex cross-section or camber so as to be substantially rigid when extended.

In a preferred construction the several tapes are mounted in a common holder having chambers to receive the several wound tape rolls and provided with openings or exit guides through which the tapes are drawn or fed when, the rod is extended and collapsed. Means may be provided for feeding the several tapes from the holder simultaneously, such means preferably 40 comprising sprocket wheels the teeth of which engage in sprocket holes in the tapes.

The engaging edges of the tapes may be held together at spaced intervals by clips which may be of slotted torm and, when a common holder is provided, the clips are preferably arranged so that they are engaged by the tapes automatically at spaced intervals as the tapes are drawn or fed from the holder. Alternatively the edges of the tapes may be so shaped and/or formed. that the engaging edges or adjacent tapes interlock either automatically as the tapes are fed from the holder or can readily be locked together by means of a suitable device applied to such edges.

Thus, for example, the edges of the tapes may be provided with teeth and/or slots which interengage when the edges are held together by any suitable form of clip or other device or the teeth or. slots may be formed, for example, sloped and/ornotched so that'the engaging edges interlock rigidly with one another after the manner of the well known flexible interlocking slidingclasp type fastener or one edge ofeach tape may be turned inwardlyor otherwise formed with longitudinal' slots -or grooves to receive the edge of the adjacent tape, rings closely encircling the rod, or other means being provided to retain this edge in position in the slot or groove.

Referring more particularly to Figures 1-3, the device shown consists of two main elements: A

\ collapsible rod or pole P and an erecting niecha-I nism M which, has the triple function of erecting the rod P, forming its supporting base, and storing it withimin compact form,--when not'in use.

The rod P, Figures 11 and 12, consists 'of a structure composed of three substantially identical flexible metal tapes l8,- I], I2 of suitable material such as spring steel having a curved trans-- verseor concave-convex form uniform throughout their whole length so that the tapes have an inherent tendency to assume a rectilinear state to increase their-individual stifiness.' These tapes are disposed withrespect to-each other to form,

when the rod'is' erected, a hollow cylinder "of triangular cross-section, the convex sides of the tapes, in the example shown, being turned inwards while their edges rest in contact upon. those of" the adjacent tapes. Rod P may be considered as a composite structural member subject, principally to direct axial which, in the case of the composite structure under description, will inanifest itself as v a tendency of the individual tapes'axially to slide upon each other. In order to prevent failure of the structure due to this tendency, sliding is eliminated by the provision of teeth l3 along the edges of the tapes, which mesh with the teeth of the adjacent tapes, as the rod is being erected.

Due to longitudinal compressive stresses, the individual tapes will tend to buckle and separate from each other, and, to avoid this, rings l4 shown in greater detail in Figure 9, are provided along the structure, which are held in place by the friction caused by pressure of the radial protrusions I5 of the rings against the elastically yielding walls of the tapes, and are spaced from each other sufficiently close to insure safe lateral support.

In the construction shown in the drawings each individual tape under compression may be considPed as a column in the adequate distribution of the fings along the rod. Thus, when'the rod, in its normal function, is subject to bending and compressive forces dueto wind pressure and the rods own weight, the compressive stresses will increase from zero at the top to a maximum at the base, and the rings, in order to have the least number of them, should be spaced more widely apart toward the top or free end. The correct spacing of the rings may be determined according to a suitable rule as, for example, an adaptation of Eulers column formula.

The three tapes are joined permanently together at the free end by means of block l6 and screws I 1, as shown in Figures 10' and 10. When .5

it is necessary to add tothe safety of the post, guy wireshnay be attached to it, and, forthis' purpose, some of the rings are adapted to receive these guy wires, asby the provision of holes l8, as shown in Figures 13 'and 14 ,'intowhioh the terminaP'h-ooks-IQof the guy .wires 20 are inserted. In order that the rings carrying the guy ,wir'es stay in place against the downward com-- ponent ofthe pull of the wires, pins 2|, in serted in prelocated perforations in the tapes; may -b eiiipl'oyed "fortl' e rings to rest natively, the tapes themselves may be provided with .holesinto which the terminal hooks l9 of on. Altertheguy wires. are inserted in which case the pins 2 ean be dispensed with.

.g The mechanism M is completely enclosed within a housing 22 having top andbottom covers 23, 2,4 as shown in Figures 1-3. Items 25, 26, 21 are frames carrying the drums to be described presently, and'togetlier with the central frame 25 28, are securely fastened to the walls of housing 22 by means of screws shown at 29. The

f frames 25, 26, 21,28 constitute together a snug passage at 38 for the three tapes to pass through suitable guides and provide-lateral support for the rod. The tapes 'forminggthe red are indi- ,vidually loosely wound and fastened with screws on upper drums 8!, 32, 33 all rigidly mounted,,

and rotatable therewith, on shafts 34, 35, 36

*jour'naled in bushed holes in the respective frames V 25, 2s,-2,1. The three shafts 34, 3G carry at their ends bevel gears 31, 38, 39, 48 fixed thereto by means of tapered pins 4|, or other suitable means, these gears being provided to'transmit motion to shafts 35 and 35 from shaft-34;

v.Shaft 34 carries at the end opposite to bevel. 31, a spur gear 42, keyed thereto by means of tapered pin 43. Hub extension 44 of spur 42 has a slot 45 to receive one of the tongues of the floatj ing member 46 of an Oldhamcoupling. The op- "posite tongue of this floating member engages a slot 41 in hub extension of drum 48' of friction ratchet 49. This friction ratchet, constructed on the principle ofthe conventional over-running clutch, serve to lock the erecting mechanism against the efiects of the weight of rod P. It consists of the drum 48 already mentioned (see Fig. 4); provided with milled-out portions 50 whichlatter are formed with flat faces on which rollers 5| ride, which, together with hardened lining 52 forced into bore in housing 22, produce a wedging effect when drum 48 tends, dueto the weight of the rod, to rotate in a direction opposite eflfect, springs 53, acting against rollers 5|, are provided. Within the milled-out portions 58 there are further provided pins 54, rigidly riveted.

into the flange of disc 55, and which, serve to function as follows: n I

By rotating the disc in a clockwise direction by turning operating handle 59 when erecting the rod, pins 54 will push against radial surfaces sue in drum 43 thereby forcing 48 to rotate in the same direction, the wedging efiect of the rollers to that of the arrow. To initiate this wedging ing rotation to the It in the same direction.

The disc I! has an extension. I6 which serves as a journal free to'turn in bearing extension of cover 51, which acts also as a retainer for BI. Another extension 58 of disc 55, which projects into bore in 48, is provided to secure a better bearing for It and prevent wobbling. A handle 59 is provided to impart rotation to disc 55. This handle is pivoted at 60 on screws 6|, so that it may be turned upward as shown by the dot-and-dash outline 59', thus putting it out ofthe way when not in use..

Tape ii is passed over drum 62, having toothed end-plates 63, 84 securely attached thereto and which in turn is securely mounted upon shaft 65, as'by means of a'set screw 66. Shaft derives its motion'from spur gear 42, through idler spur gear 61 arranged to'rotate freely on pin 68, and through spur gear 89, securely attached to shaft 85 as by tapered pin ll, (see Fig. 8). With this gearing arrangement drums 3i and 62 will rotate in the same direction. Theteeth I! of tape ii mesh with the teeth of end-plates 63, 64, whereby the tape is propelled by the drum 62. Tape III lower drums, when the rod is being erected, their is passed over idler drum ll arranged to rotate freely on shaft I2, as shown in Fig. 6. Tape llispassed over another idler drum similar to H. As the tapes l0, II, I! leave their respective edges will come in contact and their teethwill intermesh-with' thoseof the opposite tapes.

As the tapes continue their motion upward, they will pick up rings ll, which are released one at axtime. For this .purpose, the rings are all piled up in a recess 13,Flgu re 1, before the erection of the rod. The lengths of the protrusions I! of the rings are graded so as to have those of the upper rings press against'the elastic walls of the rod more firmly than those of the lower rings, to make sure that the uppermost ring remaining in recess 13 will be carried up by frictionby the, p'ost'whenever the three uniformly'rotating pawls-ll register with notches ",Figures- 5 and 9, of the rings. The notches 16 of adjacent rings are non-coincident, so that, when the'upper ring is released as the pawls register'with its notches, "the lower rings will be "held down by the pawls, and the rings released individually. Furthermore, the notches I! are located with respect to the whole group of rings in such a way. that the release of the rings by' the uniformly rotating pawls is timed according to what manner of distribution of the rings along the post is desired. The uniformly rotating pawls I4 are carried around by the sleeve 16, each one being inserted in apertures 'in this sleeve where, within certain limits, they are free to move radially. The pawls are normally held against stops 11 by the force of the garter spring ll. Sleeve 16 has at the lower edge a gear crown.

.19 whose teeth'mesh with those of a pinion l0,

. Figures 3 and 5. Pinion Oil is keyed at upper end of shaft 8|, which is Journaled in bearings- 82, II of frame 25.. The lower end of shaft 8| a half.

rodwas erected. As the rings may have moved slightly out of their original places, due to vibration, etc., their notches might not register with the pawls as they are brought down, the result being that they will have a tendency to pile up I above the pawls. If they do pile up above the pawls, then, as: the rod is reeled in its entirety, the heads of screws I! at the free end of the rod will eventually come in contact with the protrusions ity of the uppermost ring, forcing all those rings remaining above the pawls into recess 14 as the beveled pawls spread out against the garter spring force dueto the reaction of the outside edges of the rings against the beveled 1 to this'invention has many uses. Thusfor example it can be employed. as a portable aerial or antenna for wireless transmitting and receiving m apparatus. For usein short wave apparatus, a substantially rigid and straight aerial rod having a length of, say, about fifteen feet can be obtained when using three springsteel ,tapes having widths of about an inch to an inch and a Such a wireless aerial can readily be withdrawn or extended as required and when not in use occupies only a very small space since the dimensions of the complete holder are of the order of a four inch cube; If desired the holder can be pivotally mounted on trunnions carried by a base which can be mounted, say, on

a suitable-insulating support. The angle of inclination of the rod can thus be readily adjusted to obtain directional effects. An extensible an- 35 tenna of this construction is thus extremely portable and is particularly suitable, for example, for wireless transmitters or receivers used on motorcars to be described hereafter.

' the di-pple antenna to be oriented in any desired position. Platform II, as well as sprockets I2, is, so

maybe made of suitable electrically insulating material so that the two antenna rods will remain electrically insulated from each other. Clamps Ii, 98 are attached toposts to permit electrical connectionswith transmitter or re- 55 ceiver 91 by means of leads 98, 98. The device may also be employed as a single antenna of larger dimension for medium or short wave stations, illustrated as a permanent fixture of a radio station automobile in Figure 17. In the 60 latter, the device M is shown mounted on a bracket I" suspended from the roof of the automobile body, the post being allowed to pass, through opening llll provided with trap door III.

Besides the use as collapsible antennae for ll transportable wireless stations, the collapsible rod structure according to the invention is advantage'ously suited for the construction .of a collapsible ladder in which case somewhat larger tapes will usually be required than are necessary to for a wireless aerial. It is found however that an extremely rigid rodsumciently strong to support the weightofa'climbercanbemade withthree tapes having widths of the order of four inches.

when so employed the tapes are preferably pro- 78 slots may be additional to slots provided, as described above, for the sprocket wheels used for feeding the tapes from the holder or the slots engaged by the teeth of the sprocket wheels may be used, when the ladder is extended, to support step irons or other members. If desired, the ladder, instead of consisting of one rod provided with step irons or the equivalent, may be built up of two or more of such rods with appropriate: cross or lattice members attached thereto after the rods have been extended. Thus, for example, the ladder may consist of two extensible rods spaced apart and connected by transverse members which constitute the steps or may be built up of three, four or more of such rods connected by suitable transverse lattice members so as to form a rigid tower-like structure, as shown diagrammatically in Figures 18 and 19.

In the latter, two identical structures of the type disclosed are mounted on a common support construction described above, the rod is formed by tapes of curved cross-section, it will be appreciated that flat tapes maybe used although the rod formed thereby will probably not be as strong as a rod formed with curved tapes of the same dimensions.

Furthermore, the rings I4 may-be dispense with and the tapes prevented from buckling or disengaging by having one edge thereof formed with teeth or lips I06 similar to the teeth I3 and by providing perforations I01 along the-opposite edge of the tape insuch a manner that when the rod is erected the teeth of one tape engage the perforations of the adjacent tape in the manner of the known slide fastening devices, thus ensuring a rigid self-supporting structure requiringno additional holding or locking means as shown in Figures 20 and 21. a

Alternatively, a separate locking device such as a chain or tape I00 see Fig. 22) may be provided which may be of substantially smaller width than the main tapes I0, II and I2 and is applied to the main tapes as the latter are'unwound. For this purpose, the teeth I08 of one tape engaging the holes I01 of the adjacent tape are shown provided with perforations I08 engaged by the hooklike extensions H0 of the auxiliary tape I". The auxiliary tapes may be stored, and wound and unwound in synchronlsm with ,the main tapes by the provision of suitable gear transsuch a manner that the extensions IIII readily j enter into and lock with the perforations I00.

I claim: 1. A collapsible rod comprising a plurality of resilient metal tapes each arranged to be wound into a roll, said tapes forminga hollow cylinder with each tape constituting one side of the cylinder, a plurality of discrete supporting members spaced at predetermined intervals alongsaid rod for holding together the engaging sides of the adiacent tapes, means for winding and unwinding said tapes in unison, and further means cooperatingwith said last means for simultaneously rele'asing'and applying said sup orting members,

whereby said rod may be collapsed and extended.

2. A collapsible rod comprising a plurality of concavo-convex resilient metal tapes each arranged to be wound intoa roll, said tapes forming a hollow cylinder with each tape constituting one side of the cylinder, a plurality of discrete supporting members spaced at predetermined intervals along said rod for holding together the engaging sides of adjacent tapes, means for winding and unwinding said tapes in unison, and fur-' ther means cooperating with said last mentioned means for simultaneously releasing and applying said supporting members, whereby said rod may be collapsed and extended.

3. A collapsible rod comprising a plurality of resilient metal tapes each arranged to be wound into a roll and having longitudinal toothed edges, said tapes forming a hollow cylinder with the teeth of one tape engaging the teeth oftheadjacent tape, a plurality of discrete supporting members spaced at intervals along said rod for holding together the engaging sides of adjacent tapes, meansforwinding and unwinding said tapes in unison, and further means cooperating with saidlast means for simultaneously releasing and applying said supporting members, whereby said rod may be collapsed and extended.

4. A hollow rod structure comprising a plurality of concavo-convex resilient metal tapes,

said tapes being arranged with their'convex edge.

portions engaging each other to form a hollow cylinder, and a. plurality of discrete annular'supporting elements spaced at predetermined distances apart and having inner radial extensions frictionally engaging the faces of said tapes to form a rigid structure. i

5. A hollow rod structure comprising a plurality of COHOIVO-CODVBX resilient metal tapes, said tapes being arranged with their edges engaging each other to form a hollow cylinderwith the convex sides of the tapes turned inwardly, and a plurality of discrete ring-shaped elements surrounding said cylinder at spaced'predetermined intervals, said elements having inner radial extensions frlctionally engagins'and holdrality of concavoe-convex resilient metal tapes,

saidtapes having toothed longitudinaiedges and arranged to form a hollow cylindrical rod with the teeth of one tape engaging the teeth of the adjacent tape, and a plurality of discrete ringshaped supporting elements encircling said'rod at predetermined spaced intervals, said elements having inner radial extensiifis-each frictionally engaging one of said tapesto hold adjacent tapes in firm engagement.

7. A hollow rodstructure comprising "a plurality of concave-convex resilient metal tapes, said tapes having toothed longitudinal edges and arranged to form a hollow cylindrical rod with adiacenttape, the convex side of-the tapes being turned inwardly, and a plurality of discrete the teeth of one tape enga in the teeth of the ring-shaped supporting elements encircling-said rod at predetermined spaced intervals, said eleaisa'ooa ments having inner radiarextensions frictionally engaging the sides of said tapes t hold adiacent tapes in firm en ement.

8. A hollow rod comprising three concavo convex resilient metal tapes, said tapes having toothed-edges and arranged to form a hollow cylindrical rod with the teeth of one tape engaging the teeth of the adjacent tape; the convex sides of said'tape being turned inwardly, and a plurality of discrete ring-shaped supporting elementsencircling said rod at predeter mined spaced intervals, said elements having inner extensions frictionally engaging the outer surface of said tapes so as to hold adjacent edges of said tapes in firm engagement.

9. A collapsible rod structure comprising a casing, a plurality of resilient' metal tapes capable of being wound-into'a roll. a plurality of winding drums rotatably mounted in said casing, each of said tapes being adapted to be wound upon and unwound from one of said drums, drive means for rotating said drums in unison, propelling means -for unwinding said tapes from and rewinding the same upon the respective drums, further means for guiding the tapes into marginal engagement to form a hollow cylindrical rod upon emerging from said casing during unwinding, and a plurality of supporting elements frictlonally engaging said rod at spaced intervals to hold the sides thereof in firm engagement, said elements being normally stored in said casinanand means actuated from said-drive means for applying and releasing said elements in prearranged order as said rod is extended and collapsed, respectively.

10. A collapmble rod structure comprising a casing, a plurality of resilient-metal tapes ca-' pable of being wound into aroll, a plurality of winding drums"rotatably mounted in said castapes from and rewinding the same upon the respective drums, means for guiding the tapes into marginal engagement to form a hollow cylindrical rodupon emerging from said casing during unwinding, and a plurality of ring-shaped S porting elements normally piled upon each other within said casing, said elements having inner radial extensions adapted to frictionally engage the sides of said rod to hold the sides thereof in firm'engagement, anda rotating pawl operated. from said'drive means, said pawl overlapping said elements and being adapted to engage non-coincident radial slots in said elements, whereby said elements are released-and picked up by the rod in prearranged sequence when said rod is being extended.

l1. A;collapmble rod structure comprising a casing. a plurality of winding drums rotatably mounted in said casing, a plurality of resilient metal tapes having toothed edgeseach of said .tapesbeingadapted to'be wound upon and unwound from' one of said drums, drive means for rotating said in unison. means for guiding the tapes'whereby the teeth of one tape ensaid rod'at predeterminedspaced intervals, said holding-members frictionally enga in said tapes to hold the same infirm'engage'ment, and means actuated from said drive means for applying and releasing said holding members in. prearranged order as said rod is extended and collapsed, re-

means for rotating said drums in unison, means for guiding the tapes whereby the teeth of one tape engage the teeth of the engaging tape to form a hollow cylindrical rodupon emerging from said casing during. unwinding with said tapes forming the sides-of said rod, and a plurality of ring-shaped supporting elements normally stored and piled upon each other within said casing, said elements being adapted to frictionally engage the outer sides 'of saidrod to hold saidt'apes in firm engagement, and means operated in synchronism from said drive means for releasing said elements to be frictionally engaged by the sides of said rod at predetermined spaced intervals while said rod is being extended.

13. A collapsible rod structure comprising a casing, three winding drums rotatably. mounted in said casing, three concave-convex resilient metal tapes capable of being flattened and wound into a roll and having toothed edges, each of said tapes being adapted to be wound upon and unwound from one of said drums, drive means for rotating said drums 'in unison, and means for guiding the tapes whereby the teeth of one tape engage the teeth of the adjacent tape to form a hollow cylindrical rod with the convex side of the tapes turned inwardly upon emerging from said casing while said tapes are being unwound, and a plurality of discrete hold-- ing members encircling id rod at predetermined spaced intervals, said holding members frictionally engaging said tapes to hold the same in firm engagement, and means actuated from said drive means for applying and releasing said holding members in'prearranged order as said rod is extended and collapsed; respectively.

14. A collapsible rod structure comprising a casing, three winding drums rotatably mounted in said casing, three concave-convex resilient metal tapes capable of being flattened and wound into a roll and having toothed longitudinal edges,

each of said tapes being adapted to be wound upon and unwound from one of said drums, drive for releasing said elementsain predetermined sequence while said tapes arebeing unwound.

15. A hollow rodstructure} comprising three concavo-convex resilient metal tapes having toothed longitudinal edges, said tape being arranged with the teeth of one tape engaging the teeth of the adjacent tape to form a hollow cylin-' der with the convex sides of the tapes turned inwardly, and a plurality of discrete annular supportingelements spaced at predetermined distances apart and having inner radial extensions fricticnally engaging the faces of said tapes to form a rigidstructure.

gagement.

16. A hollow rod structure comprising three resilient concave-convex metal tapes, each of said tapes having its longitudinal edges formed with a series of teeth, said tapes being arranged with the teeth 01 one tape engaging the teeth of the adjacent tape tojorm a hollow cylinder with the tapes having their convex sides turned inwardly and constituting the sides of said cylinder, and a plurality of discrete holding members encircling said cylinder at predetermined intervals and engaging said tapes to hold said tapesin firm en- 1'7. A collapmble rod'structure comprising a casing, a plurality of winding drums rotatably mounted in said casing, a plurality of resilient metal tapes having toothed longitudinal edges, each 01' said tapes being adapted to be wound upon and unwound from one of said drums. drive means for rotating said drums in unison, means for guldingsaid tapes whereby the teeth of one tape engageflie teeth of an adjacent tape to form a hollow cylindrical rod upon emerging from said casing while the tapes are being unwound, and a plurality of ring-shaped elements normally stored and piled upon each other within said casing, said elements beingadapted. to frictionally engage the outer sides of said rod to hold adjacent tapes in firm engagement, and means operated in synchronlsm with said drive means for releasing and engaging said elements with said rod at predetermined spaced intervals when said rod is being extended.

18. In'a collapsible structure as claimed in claim 9 including means for preventing collapse 0! said rod due to its own weight.

a WILLIAM DUBEJER. 

